Radiolabeled Insecticides, Synthesis of Rotenon-6a-C¹⁴ on a Semimicro Scale

Abstract

Reaction of 2 mmoles of methyl bromoacetate-1 -C14 with 3 mmoles of derritol produced 6a,12a-dehydrorotenone-6a-C14 in approximately 50% yield. Sodium boron hydride reduction gave the 12-hydroxy-6a-C14 intermediate and subsequent Oppenauer oxidation produced rotenone-6a-C14. Yields for conversion of nonradioactive 6a,12a-dehydrorotenone to rotenone were 17 to 25% but, with radioactive material of 2.36 me. per mmole, the yield was only 7.5%. Other oxidation procedures for the reduction product of 6a,1 2a-dehydrorotenone are considered, as are possible explanations for the lower yield with the radioactive material. Rotenoids, in the form of ground " derris roots, have been used for insect control and as fish poisons for more than a century. Rotenone, the principal active ingredient, has short residual action and relatively high selectivity as an insecticide. However, it may be very toxic to mammals and produce tissue damage at low dietary levels under certain conditions (14,16). The

Rotenone photodecomposition

“…Natural rotenone (Aldrich Chemical Co., Milwaukee, Wis.) was recrystallized from methanol [mp 162-3"C, reported as 162-3°C by Nishizawa and Casida (1965), and 167-8°C by Crombie (1963); [cu]*~D -226" in benzene, reported as [OI]~OD -228" in benzene by Crombie (1963)l. Natural rotenone (Aldrich Chemical Co., Milwaukee, Wis.) was recrystallized from methanol [mp 162-3"C, reported as 162-3°C by Nishizawa and Casida (1965), and 167-8°C by Crombie (1963); [cu]*~D -226" in benzene, reported as [OI]~OD -228" in benzene by Crombie (1963)l.…”

“…Chemicals. Natural rotenone (Aldrich Chemical Co., Milwaukee, Wis.) was recrystallized from methanol [mp 162-3°C, reported as 162-3°C by Nishizawa and Casida (1965), and 167-8°C by Crombie (1963); [a]25D -226°in benzene, reported as [ ]20 -228°in benzene by Crombie (1963)].…”

Sensitized photodecomposition and photosensitizer activity of pesticide chemicals exposed to sunlight on silica gel chromatoplates

“…The C14-labeled pesticide chemicals studied were prepared in this laboratory, in which case the labeled position has been reported (Krishna et al, 1962; Kuwatsuka and Casida, 1965;Nishizawa and Casida, 1965;Yamamoto and Casida, 1968), or they were obtained as follows: aldrin-C14, dieldrin-C14, endrin-C14, and 3,4,5-trimethylphenyl methylcarbamate carbonyl-C14 (SD-8530) (Shell Development Co., Modesto, Calif.); 2-dimethylamino-4,5-dimethyl-6-pyrimidyl dimethylcarbamate carbonyl-C14 (pirimicarb) (Alan Calderbank, Division of Entomology, University of California, Berkeley, Calif. 94720 Plant Protection Ltd., Jealott's Hill, England); Sumithion-O-methyl-C14 (Yoshihiko Nishizawa, Sumitomo Chemical Co., Osaka, Japan); Imidan-carbonyl-C14 and Dyfonatering-C14 (Julius Menn, Stauffer Chemical Co., Mountain View, Calif.); malathion-l,2-succinyl-C14 and DDT-ring-C14 (World Health Organization, Geneva, Switzerland); diazinon-pyrimidyl-2-C14 and isolan-carbonyl-C14 (Geigy Chemical Co., Ardsley, N.Y.); 2,4-D-a-C'4 (New England Nuclear Corp., Boston, Mass. ); Dessin-ring-C14 (Union Carbide Chemicals Co., South Charleston, W. Va.); and 2-jec-butyl-4,6-dinitrophenol-ring-C14 (DNBP) (obtained by hydrolysis of Dessin-ring-C14 and supplied by Suresh Bandal, University of Calif., Berkeley).…”

The insecticide target in the PSST subunit of complex I

“…Recognition of a specific binding site for an insecticide in complex I was first achieved with [ 14 C] 1a (2.4 mCi mmol −1 )32 and bovine heart electron transport particles (ETP) (Fig 5). 33 A centrifugation assay was used with bovine serum albumin (BSA) washes of the ETP to minimize non‐specific binding.…”